Field
The present disclosure relates to the manufacture of molding elements for vulcanizing and molding tires, and more particularly to the manufacture of molding elements obtained by the selective melting of a powder.
Description off Related Art
It is known practice to create a molding element using a method of selective melting, more commonly referred to as sintering. This method uses a beam of energy to melt a powder. A “beam of energy” means electromagnetic radiation (for example a laser beam) or a beam of particles (for example an electron beam).
A sintering method using a laser, hereinafter referred to as a laser sintering method, is known from document EP1641580. In that document, a first layer of powder is spread on a support plate by a layering member. All or some of the particles of powder of this first layer of powder are then agglomerated by the laser beam according to the shape of the object that is to be obtained. Once this step has been performed, a second layer of powder is spread on the first layer of powder so that it in turn can be selectively melted using the laser. By repeating these operations of spreading a layer and fusing using a laser, a sintered object is built up layer by layer.
Document WO2010072960 discloses a method for manufacturing a molding element using sintering. In that method, rigid secondary elements are produced at the same time as the molding element, so as to support this molding element. The molding element thus comprises a bar, denoted 24 in that document, and fins 26. The secondary elements notably comprise support parts 36 and joining parts 28. The support parts 36 have a thickness corresponding substantially to the thickness of the surface portion of the molding element that they support and the joining parts have a smaller thickness than these support parts so that they can form break lines facilitating the detachment of the molding element from the support plate. However, the presence of these joining parts of a smaller thickness than the molding element means that this molding element is supported partially by unsintered powder, as it is being manufactured. Now, the inventors have found that, for certain shapes of molding element, this partial support can lead to problems in the manufacture of this molding element.
There is therefore a need to improve the manufacture of molding elements using sintering, while at the same time optimizing the use of the secondary elements supporting these molding elements.